A Lower Rate of Hyposmia in Non-Ashkenazi Jewish Patients with Parkinson's Disease: Motor and Non-motor Disease Characteristics in Different Ethnic Groups in Israel.

BACKGROUND

Little is known about phenotypical variations among ethnic groups in patients with Parkinson's disease (PD) in Israel. Clinical characteristics of non-Ashkenazi Jews (NAJ) are scantly described.

OBJECTIVES

To describe clinical aspects of PD in ethnic groups in Israel, focusing on NAJ and Ashkenazi Jews (AJ).

METHODS

In this cross-sectional retrospective study, we collected demographic, genetic, and clinical characteristics of patients from different ethnic Jewish backgrounds. Ethnic groups included AJ; North African Jews (NAFJ); oriental Jews (OJ) originating from Iran, Iraq, and Buchara; Balkan Jews; Yemenite Jews (YJ); and Jews of mixed origin. Clinical characteristics included hyposmia, urinary complaints, constipation, and rapid eye movement sleep behavioral disorder. Cognitive complaints, motor features, levodopa-induced dyskinesia, and motor fluctuations were collected. Motor part of the MDS-UPDRS and Hoehn and Yahr scores were collected.

RESULTS

The study comprised 174 PD Jewish patients (63.2% AJ, 56.4% males). The age at onset was 65.3 ± 10.2 years; 106 patients (60.9%) were genotyped (17 glucocerebrosidase [16.0%], 13 leucine-rich repeat kinase 2 [LRRK2] [12.3%]). Rates of hyposmia were significantly higher in AJ than NAJ (56.6% vs. 39.5%, respectively, P = 0.003). No significant differences were found in motor features in all variables. Of 13 AJ patients carrying the LRRK2 mutation, only one had hyposmia. Three patients with LRRK2 were NAJ.

CONCLUSIONS

Hyposmia is less prevalent in PD patients of NAJ origin than in AJ. The rate of hyposmia in NAFJ patients is particularly low. The rate of other non-motor features is similar between NAJ and AJ patients.